Network security cameras fall into two general categories based on whether they were designed for indoor use only or both indoor and outdoor use. Indoor cameras are built simpler than outdoor security cameras because the lighting conditions indoor tend to be more consistent, and physical demands are much easier to handle. Outdoor security cameras require protection from the external environment as well as auto iris lenses that regulate the amount of light is let through the lenses.
Fixed network security cameras have a fixed field of view that is a result of its mounting position. It needs to be mounted with a clear line of sight but also generally serves well as a deterrent where the owner wants the camera in plain sight. Most models are designed to allow the lens to be changed as needed.
Fixed dome cameras are similar to fixed cameras except that it comes pre-installed in small dome housings. Its housing offers a more discreet option than the fixed camera. The limitation of a fixed dome camera is realized once the owner wants to change the lens.
Because of the design of the housing, it is usually very difficult if not impossible by manufacturers design to change the lens. They come in different types of enclosures that protect it from vandals and other physical threats.
The PTZ camera or PTZ dome cameras are the cool ones in movies that can pan, tilt, and zoom in and out. The control can be automatic or manual and the commands are sent over the same network cables as the video signal. No additional wiring needed, unlike analog security cameras.